Schizophrenia and sleeping problems linked?

Recent findings that a gene associated with schizophrenia also causes abnormal sleep patterns in mice have led scientists to ponder whether the mental illness and sleep disturbance could be genetically linked. If true, the research could lead to better diagnosis and control of schizophrenia.

People with schizophrenia often report trouble sleeping. This led scientists to look at the sleeping patterns of mice with a defect in the SNAP25 gene, a mouse strain often used in the study of schizophrenia. Previous studies have also linked SNAP25 to schizophrenia in people.

The researchers found that these mice were not waking and sleeping in the same patterns as normal mice kept under the same conditions of light and dark.

The brain has its own internal clock, called the suprachiasmatic nucleus (SCN), which gathers information about night and day from the eyes and relays it to the rest of the body. When the researchers looked at the SCN of the mice they could find nothing wrong with the clock. However, there were problems in the production of hormones by the SCN, which it uses to communicate with the rest of the body. This meant that other parts of the mouse’s body were not being kept in sync with night and day.

The findings suggest that the sleep disturbance experienced by people with schizophrenia is directly linked to the condition and not a side effect of medication or lifestyle. Other recent studies of patients with schizophrenia have added support to this theory.

As sleep disturbance is often experienced before other schizophrenic symptoms this research could help in the early diagnosis of the condition. It could also help doctors prescribe medication to control the hormonal signals from the SCN to improve the lives of people with the illness.